OP0220 CRITERIA ASSOCIATED WITH TREATMENT DECISIONS IN JUVENILE IDIOPATHIC ARTHRITIS WITH A FOCUS ON ULTRASONOGRAPHY: RESULTS FROM THE JIRECHO COHORT.
Authors: S. Mahmoud, S. Jousse-Joulin, A. Saraux, P. Dusser, C. Borocco, C. Galeotti, A. Von Scheven, M. Hofer, B. Bader-Meunier, F. Aeschlimann, S. Breton, L. Sparsa, C. Aurélia, G. Mouterde, L. Rossi-Semerano, V. Devauchelle-Pensec
Journal: Annals of the Rheumatic Diseases (2022)

Background Treatment of children with juvenile idiopathic arthritis (JIA) is a major challenge in paediatric rheumatology. The presence of synovitis, which is difficult to detect in children, is associated with structural damage. Musculoskeletal ultrasonography (MSUS) can be used in JIA patients to reveal subclinical synovitis. Objectives Our aim was to determine if the use of MSUS is associated with therapeutic modifications in JIA. Secondary outcomes were to identify other factors associated with therapeutic modifications. Methods We conducted an observational study based on the JIRECHO multicentre cohort which was developed to provide a systematic MSUS follow-up for JIA patients. Follow-up occurred every six months and included clinical and US examinations. We included children who underwent MSUS of the elbows, wrists, second metacarpophalangeal joints, knees and ankles. Synovitis in US was defined by the presence of joint effusion and/or synovial hypertrophy in B-mode (≥ grade 1) associated or not with Doppler signals (≥ grade 1). US was performed by expert sonographers with good experience in the field of JIA who previously participated in the study of the reliability of the OMERACT paediatric US synovitis definitions and scoring system in JIA (1). Clinical and biological data, disease activity score and information on therapeutics were collected. Results We included 112 patients with 185 visits in total. Three groups of patients were defined according to their therapeutic status: increased(22%), decreased(14%) or stable(64%) treatment. First, we compared patients with treatment escalation with the other patients. Patients with “increased treatment” had more synovitis in B-mode US than the other patients (80% vs. 65%, p=0.06). There was no difference for the presence of synovitis in Power Doppler (PD) US (30% vs 23%, p=0.4). Patient’s and physician’s visual analogue scale (VAS) scores were significantly higher in patients with therapeutic escalation [3.3 vs 1.7, p&lt;0.01 and 3.6 vs 1.6, p&lt;0.0001] as well as disease activity score and inflammatory biological markers. Then, we compared patients with therapeutic de-escalation with the other patients. There was no difference in the presence of synovitis in US when compared with patients with stable treatment (62% vs. 69%, p=0.5) but there was less synovitis in B-mode ≥ grade 2 (8% vs. 24%, p=0.05). We performed ROC curves analysis that showed that the sensitivity and specificity of the US in B-mode was similar to the physician’s VAS, disease score activity or inflammatory biological markers (Figure 1). Figure 1. ROC curves for clinical and biological items and US in B-mode in patients with « therapeutic escalation » Conclusion In our study, MSUS of ten joints was not statistically associated with treatment escalation or de-escalation in B-mode and PD in patients with JIA. References [1]Rossi-Semerano, L. et al. Application of the OMERACT synovitis ultrasound scoring system in juvenile idiopathic arthritis: a multicenter reliability exercise. Rheumatol. Oxf. Engl. (2020) doi:10.1093/rheumatology/keaa804. Disclosure of Interests None declared